Circuit-breaker.



m. 695,!34. Patented Mar. u, I902.

c. c. BADEAU.

I CIRCUIT BREAKER.

(No Model.)

- Inventon Charles QBadeau.

Wifnesses.

UNITED STATES PATENT OFFICE.

CHARLES C. BADEAU, OF SOIIENECTADY, NEW YORK, ASSIGNOR TO GEN- ERALELECTRIC COMPANY, A CORPORATION OF NEIV YORK.

CIRCUIT-BREAKER.

SPEGEFICATION forming part of Letters Patent No. 695,134, dated March11, 1902.

Application filed July 25, 1901. Serial No. 69,647. (No model.)

To all whom it may concern:

Be it known that I, CHARLES C. BADEAU, a citizen of the United States,residingat Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in CircuitBreakers, (CaseNo. 2,205,) of which the following is a specification.

This invention relates to automatic circuitbreakcrs, the object being torender more scnsitive the tripping mechanism and to counterbalance theeffects of friction and other causes which contribute to an uncertaintyof the tripping-point of the circuit-breaker.

In carrying out the invention I provide the tripping-armature with anauxiliary magnetic field of suflicient density to overcome the frictionof the moving parts and counterbalance the normal tension of thecalibrating-spring by which I render the armature free to obey a smallerexcess of current than where these opposing tendencies must be overcomeby the load-current. Thus the device will be free to respond at adefinite load-current, the preliminary strain of the calibratin -springbe ing counteracted an d a greater aggregate field density provided forthe trip-armature.

The novel features of my invention will be more particularly hereinafterdescribed, and will be definitely indicated in the claims appended tothis specification.

In the accompanying drawings, which illustrate the invention, Figure 1is a sectional view showing a tripping-armature of an automaticcircuit-breaker and its calibratingspring and the auxiliary magnetopposing the tension of the spring. Fig. 2 is a side elevation of aknown type of circuit breaker to which the improvements have been added.

Referring, first, to Fig. 1, 1 represents an clectromagnet which may bepermanently excited by a shunt-circuit or by an independent source ofcurrent, the core and pole-pieces 2 2 of which maintain a continuousfield of force acting upon a trip-armature 3. It is not absolutelyessential that this continuous field of force should be furnished by anelectromagnet, as a permanent magnet might in some cases be employed. Tothe trip-armature is connected through a lever a retracting device, suchas a spring i, adjusted by a screw 5, so as to determinothe calibrationof the circuit-breaker. The particular type of tripping device shown isone adapted for currents of very heavy amperage, to which the inventionis particularly well adapted. In this type the field of force of thecircuit-breaker terminal itself is relied upon to trip thecircuit-breaker. The end of this stud is seen at 6, Fig. 1. Thepole-pieces 2 2 overlap the sides of this terminal or stud and havemagnetism induced by the field of force of the heavy current passingthrough the stud when the circuitis closed. Thus the friction of theparts and the initial tension of the calibrating-spring is compensatedby the auxiliary magnet, and the only work to be perfor med by thecurrent passing through the circuit governed by the circuit-breaker isthe additional strain imposed on the spring to trip the mechanism, thusinsuring greater precision of operation at a definite load-current.Moreover, the extra field of force furnished creates a greater aggregatemagnetic density and adds greatly to the tripping power of the currentpassing through the breaker, since the interfering effects of frictionin the toggles and the increasing tension of the spring are lesseffective with the increased magnetic density.

In Fig. 2 the device is shown as applied to a modern type of automaticcircuit-breaker of large capacity, in which 7 represents a heavybridging-contact normally completing the circuit and 8 a shunt-contactthrough which the final break is made. 9 is a lever pivoted to the frameand loosely connected to the triparmature 3, which when operated strikesa pin 16 and knocks down a toggle which releases the circuit-breaker.These parts are shown merely by way of example, as they form no part ofmy present invention. 6 6 represent the studs or terminals which connectthrough the rear of a'supportingboard 11 with the control-circuit.

That I claim as new, and desire to secure by Letters Patent of theUnited States, is-

1. In combination with a circuit-breaker and its magnetic trippingdevices, an auxiliary d evice to overcome the initial tension of theretractile agent for the trip-armature.

In an automatic circuit-breaker,the com bination of magnetictrippingdevices, a retractile agent, and an auxiliary magnet forincreasing the density of the tripping field of force.

3. In an automatic circuit-breaker,the combination with magnetictripping devices, of

a separately-excited auxiliary magnet acting attractively upon thearmature to assist the magnetic tripping devices. 7

I 4. In an automatic circuit-breaker, tripping devices controlled by amagnetic circuit embracing the circuit-breaker terminal, and anauxiliary magnet normally furnishing a definite magnetizing force tosaid tripping magnet.

5. An automatic circuit-breaker provided with a magnetic yoke around acircuit-ter- CHARLES C. BADEAU.

Witnesses:

BENJAMIN B. HULL, EDWARD WILLIAMS,J r.

